MODULE_PARM_DESC(ovl_redirect_dir_def,
"Default to on or off for the redirect_dir feature");
+static bool ovl_index_def = IS_ENABLED(CONFIG_OVERLAY_FS_INDEX);
+module_param_named(index, ovl_index_def, bool, 0644);
+MODULE_PARM_DESC(ovl_index_def,
+ "Default to on or off for the inodes index feature");
+
static void ovl_dentry_release(struct dentry *dentry)
{
struct ovl_entry *oe = dentry->d_fsdata;
if (oe) {
unsigned int i;
- dput(oe->__upperdentry);
- kfree(oe->redirect);
for (i = 0; i < oe->numlower; i++)
dput(oe->lowerstack[i].dentry);
kfree_rcu(oe, rcu);
.d_weak_revalidate = ovl_dentry_weak_revalidate,
};
+static struct kmem_cache *ovl_inode_cachep;
+
+static struct inode *ovl_alloc_inode(struct super_block *sb)
+{
+ struct ovl_inode *oi = kmem_cache_alloc(ovl_inode_cachep, GFP_KERNEL);
+
+ oi->cache = NULL;
+ oi->redirect = NULL;
+ oi->version = 0;
+ oi->flags = 0;
+ oi->__upperdentry = NULL;
+ oi->lower = NULL;
+ mutex_init(&oi->lock);
+
+ return &oi->vfs_inode;
+}
+
+static void ovl_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+
+ kmem_cache_free(ovl_inode_cachep, OVL_I(inode));
+}
+
+static void ovl_destroy_inode(struct inode *inode)
+{
+ struct ovl_inode *oi = OVL_I(inode);
+
+ dput(oi->__upperdentry);
+ kfree(oi->redirect);
+ mutex_destroy(&oi->lock);
+
+ call_rcu(&inode->i_rcu, ovl_i_callback);
+}
+
static void ovl_put_super(struct super_block *sb)
{
struct ovl_fs *ufs = sb->s_fs_info;
unsigned i;
+ dput(ufs->indexdir);
dput(ufs->workdir);
+ ovl_inuse_unlock(ufs->workbasedir);
+ dput(ufs->workbasedir);
+ if (ufs->upper_mnt)
+ ovl_inuse_unlock(ufs->upper_mnt->mnt_root);
mntput(ufs->upper_mnt);
for (i = 0; i < ufs->numlower; i++)
mntput(ufs->lower_mnt[i]);
return err;
}
+/* Will this overlay be forced to mount/remount ro? */
+static bool ovl_force_readonly(struct ovl_fs *ufs)
+{
+ return (!ufs->upper_mnt || !ufs->workdir);
+}
+
/**
* ovl_show_options
*
if (ufs->config.redirect_dir != ovl_redirect_dir_def)
seq_printf(m, ",redirect_dir=%s",
ufs->config.redirect_dir ? "on" : "off");
+ if (ufs->config.index != ovl_index_def)
+ seq_printf(m, ",index=%s",
+ ufs->config.index ? "on" : "off");
return 0;
}
{
struct ovl_fs *ufs = sb->s_fs_info;
- if (!(*flags & MS_RDONLY) && (!ufs->upper_mnt || !ufs->workdir))
+ if (!(*flags & MS_RDONLY) && ovl_force_readonly(ufs))
return -EROFS;
return 0;
}
static const struct super_operations ovl_super_operations = {
+ .alloc_inode = ovl_alloc_inode,
+ .destroy_inode = ovl_destroy_inode,
+ .drop_inode = generic_delete_inode,
.put_super = ovl_put_super,
.sync_fs = ovl_sync_fs,
.statfs = ovl_statfs,
.show_options = ovl_show_options,
.remount_fs = ovl_remount,
- .drop_inode = generic_delete_inode,
};
enum {
OPT_DEFAULT_PERMISSIONS,
OPT_REDIRECT_DIR_ON,
OPT_REDIRECT_DIR_OFF,
+ OPT_INDEX_ON,
+ OPT_INDEX_OFF,
OPT_ERR,
};
{OPT_DEFAULT_PERMISSIONS, "default_permissions"},
{OPT_REDIRECT_DIR_ON, "redirect_dir=on"},
{OPT_REDIRECT_DIR_OFF, "redirect_dir=off"},
+ {OPT_INDEX_ON, "index=on"},
+ {OPT_INDEX_OFF, "index=off"},
{OPT_ERR, NULL}
};
config->redirect_dir = false;
break;
+ case OPT_INDEX_ON:
+ config->index = true;
+ break;
+
+ case OPT_INDEX_OFF:
+ config->index = false;
+ break;
+
default:
pr_err("overlayfs: unrecognized mount option \"%s\" or missing value\n", p);
return -EINVAL;
}
#define OVL_WORKDIR_NAME "work"
+#define OVL_INDEXDIR_NAME "index"
-static struct dentry *ovl_workdir_create(struct vfsmount *mnt,
- struct dentry *dentry)
+static struct dentry *ovl_workdir_create(struct super_block *sb,
+ struct ovl_fs *ufs,
+ struct dentry *dentry,
+ const char *name, bool persist)
{
struct inode *dir = dentry->d_inode;
+ struct vfsmount *mnt = ufs->upper_mnt;
struct dentry *work;
int err;
bool retried = false;
+ bool locked = false;
err = mnt_want_write(mnt);
if (err)
- return ERR_PTR(err);
+ goto out_err;
inode_lock_nested(dir, I_MUTEX_PARENT);
+ locked = true;
+
retry:
- work = lookup_one_len(OVL_WORKDIR_NAME, dentry,
- strlen(OVL_WORKDIR_NAME));
+ work = lookup_one_len(name, dentry, strlen(name));
if (!IS_ERR(work)) {
struct iattr attr = {
if (retried)
goto out_dput;
+ if (persist)
+ goto out_unlock;
+
retried = true;
ovl_workdir_cleanup(dir, mnt, work, 0);
dput(work);
inode_unlock(work->d_inode);
if (err)
goto out_dput;
+ } else {
+ err = PTR_ERR(work);
+ goto out_err;
}
out_unlock:
- inode_unlock(dir);
mnt_drop_write(mnt);
+ if (locked)
+ inode_unlock(dir);
return work;
out_dput:
dput(work);
- work = ERR_PTR(err);
+out_err:
+ pr_warn("overlayfs: failed to create directory %s/%s (errno: %i); mounting read-only\n",
+ ufs->config.workdir, name, -err);
+ sb->s_flags |= MS_RDONLY;
+ work = NULL;
goto out_unlock;
}
if (ovl_dentry_remote(path->dentry))
*remote = true;
+ /*
+ * The inodes index feature needs to encode and decode file
+ * handles, so it requires that all layers support them.
+ */
+ if (ofs->config.index && !ovl_can_decode_fh(path->dentry->d_sb)) {
+ ofs->config.index = false;
+ pr_warn("overlayfs: fs on '%s' does not support file handles, falling back to index=off.\n", name);
+ }
+
return 0;
out_put:
size_t size, int flags)
{
struct dentry *workdir = ovl_workdir(dentry);
- struct inode *realinode = ovl_inode_real(inode, NULL);
+ struct inode *realinode = ovl_inode_real(inode);
struct posix_acl *acl = NULL;
int err;
err = ovl_xattr_set(dentry, handler->name, value, size, flags);
if (!err)
- ovl_copyattr(ovl_inode_real(inode, NULL), inode);
+ ovl_copyattr(ovl_inode_real(inode), inode);
return err;
struct path upperpath = { };
struct path workpath = { };
struct dentry *root_dentry;
- struct inode *realinode;
struct ovl_entry *oe;
struct ovl_fs *ufs;
struct path *stack = NULL;
if (!ufs)
goto out;
- init_waitqueue_head(&ufs->copyup_wq);
ufs->config.redirect_dir = ovl_redirect_dir_def;
+ ufs->config.index = ovl_index_def;
err = ovl_parse_opt((char *) data, &ufs->config);
if (err)
goto out_free_config;
if (err)
goto out_put_upperpath;
+ err = -EBUSY;
+ if (!ovl_inuse_trylock(upperpath.dentry)) {
+ pr_err("overlayfs: upperdir is in-use by another mount\n");
+ goto out_put_upperpath;
+ }
+
err = ovl_mount_dir(ufs->config.workdir, &workpath);
if (err)
- goto out_put_upperpath;
+ goto out_unlock_upperdentry;
err = -EINVAL;
if (upperpath.mnt != workpath.mnt) {
pr_err("overlayfs: workdir and upperdir must be separate subtrees\n");
goto out_put_workpath;
}
+
+ err = -EBUSY;
+ if (!ovl_inuse_trylock(workpath.dentry)) {
+ pr_err("overlayfs: workdir is in-use by another mount\n");
+ goto out_put_workpath;
+ }
+
+ ufs->workbasedir = workpath.dentry;
sb->s_stack_depth = upperpath.mnt->mnt_sb->s_stack_depth;
}
err = -ENOMEM;
lowertmp = kstrdup(ufs->config.lowerdir, GFP_KERNEL);
if (!lowertmp)
- goto out_put_workpath;
+ goto out_unlock_workdentry;
err = -EINVAL;
stacklen = ovl_split_lowerdirs(lowertmp);
pr_err("overlayfs: failed to clone upperpath\n");
goto out_put_lowerpath;
}
+
/* Don't inherit atime flags */
ufs->upper_mnt->mnt_flags &= ~(MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME);
sb->s_time_gran = ufs->upper_mnt->mnt_sb->s_time_gran;
- ufs->workdir = ovl_workdir_create(ufs->upper_mnt, workpath.dentry);
- err = PTR_ERR(ufs->workdir);
- if (IS_ERR(ufs->workdir)) {
- pr_warn("overlayfs: failed to create directory %s/%s (errno: %i); mounting read-only\n",
- ufs->config.workdir, OVL_WORKDIR_NAME, -err);
- sb->s_flags |= MS_RDONLY;
- ufs->workdir = NULL;
- }
-
+ ufs->workdir = ovl_workdir_create(sb, ufs, workpath.dentry,
+ OVL_WORKDIR_NAME, false);
/*
* Upper should support d_type, else whiteouts are visible.
* Given workdir and upper are on same fs, we can do
} else {
vfs_removexattr(ufs->workdir, OVL_XATTR_OPAQUE);
}
+
+ /* Check if upper/work fs supports file handles */
+ if (ufs->config.index &&
+ !ovl_can_decode_fh(ufs->workdir->d_sb)) {
+ ufs->config.index = false;
+ pr_warn("overlayfs: upper fs does not support file handles, falling back to index=off.\n");
+ }
}
}
else if (ufs->upper_mnt->mnt_sb != ufs->same_sb)
ufs->same_sb = NULL;
+ if (!(ovl_force_readonly(ufs)) && ufs->config.index) {
+ /* Verify lower root is upper root origin */
+ err = ovl_verify_origin(upperpath.dentry, ufs->lower_mnt[0],
+ stack[0].dentry, false, true);
+ if (err) {
+ pr_err("overlayfs: failed to verify upper root origin\n");
+ goto out_put_lower_mnt;
+ }
+
+ ufs->indexdir = ovl_workdir_create(sb, ufs, workpath.dentry,
+ OVL_INDEXDIR_NAME, true);
+ if (ufs->indexdir) {
+ /* Verify upper root is index dir origin */
+ err = ovl_verify_origin(ufs->indexdir, ufs->upper_mnt,
+ upperpath.dentry, true, true);
+ if (err)
+ pr_err("overlayfs: failed to verify index dir origin\n");
+
+ /* Cleanup bad/stale/orphan index entries */
+ if (!err)
+ err = ovl_indexdir_cleanup(ufs->indexdir,
+ ufs->upper_mnt,
+ stack, numlower);
+ }
+ if (err || !ufs->indexdir)
+ pr_warn("overlayfs: try deleting index dir or mounting with '-o index=off' to disable inodes index.\n");
+ if (err)
+ goto out_put_indexdir;
+ }
+
+ /* Show index=off/on in /proc/mounts for any of the reasons above */
+ if (!ufs->indexdir)
+ ufs->config.index = false;
+
if (remote)
sb->s_d_op = &ovl_reval_dentry_operations;
else
sb->s_d_op = &ovl_dentry_operations;
+ err = -ENOMEM;
ufs->creator_cred = cred = prepare_creds();
if (!cred)
- goto out_put_lower_mnt;
+ goto out_put_indexdir;
/* Never override disk quota limits or use reserved space */
cap_lower(cred->cap_effective, CAP_SYS_RESOURCE);
mntput(upperpath.mnt);
for (i = 0; i < numlower; i++)
mntput(stack[i].mnt);
- path_put(&workpath);
+ mntput(workpath.mnt);
kfree(lowertmp);
if (upperpath.dentry) {
- oe->__upperdentry = upperpath.dentry;
- oe->impure = ovl_is_impuredir(upperpath.dentry);
+ oe->has_upper = true;
+ if (ovl_is_impuredir(upperpath.dentry))
+ ovl_set_flag(OVL_IMPURE, d_inode(root_dentry));
}
for (i = 0; i < numlower; i++) {
oe->lowerstack[i].dentry = stack[i].dentry;
root_dentry->d_fsdata = oe;
- realinode = d_inode(ovl_dentry_real(root_dentry));
- ovl_inode_init(d_inode(root_dentry), realinode, !!upperpath.dentry);
- ovl_copyattr(realinode, d_inode(root_dentry));
+ ovl_inode_init(d_inode(root_dentry), upperpath.dentry,
+ ovl_dentry_lower(root_dentry));
sb->s_root = root_dentry;
kfree(oe);
out_put_cred:
put_cred(ufs->creator_cred);
+out_put_indexdir:
+ dput(ufs->indexdir);
out_put_lower_mnt:
for (i = 0; i < ufs->numlower; i++)
mntput(ufs->lower_mnt[i]);
kfree(stack);
out_free_lowertmp:
kfree(lowertmp);
+out_unlock_workdentry:
+ ovl_inuse_unlock(workpath.dentry);
out_put_workpath:
path_put(&workpath);
+out_unlock_upperdentry:
+ ovl_inuse_unlock(upperpath.dentry);
out_put_upperpath:
path_put(&upperpath);
out_free_config:
};
MODULE_ALIAS_FS("overlay");
+static void ovl_inode_init_once(void *foo)
+{
+ struct ovl_inode *oi = foo;
+
+ inode_init_once(&oi->vfs_inode);
+}
+
static int __init ovl_init(void)
{
- return register_filesystem(&ovl_fs_type);
+ int err;
+
+ ovl_inode_cachep = kmem_cache_create("ovl_inode",
+ sizeof(struct ovl_inode), 0,
+ (SLAB_RECLAIM_ACCOUNT|
+ SLAB_MEM_SPREAD|SLAB_ACCOUNT),
+ ovl_inode_init_once);
+ if (ovl_inode_cachep == NULL)
+ return -ENOMEM;
+
+ err = register_filesystem(&ovl_fs_type);
+ if (err)
+ kmem_cache_destroy(ovl_inode_cachep);
+
+ return err;
}
static void __exit ovl_exit(void)
{
unregister_filesystem(&ovl_fs_type);
+
+ /*
+ * Make sure all delayed rcu free inodes are flushed before we
+ * destroy cache.
+ */
+ rcu_barrier();
+ kmem_cache_destroy(ovl_inode_cachep);
+
}
module_init(ovl_init);
projects / mirror_ubuntu-bionic-kernel.git / blobdiff